Lily: Whoa. What do you think came between Robin and Jessica?
Ted: Much like our friends, the Space Teens, I think I can solve this crime with math. Okay. Okay, here is a Christmas card that Jessica sent Robin. Lily, how old would you say that kid is?
Lily: Four years, three months.
Ted: Which means Jessica got pregnant five years ago. Right around the time she and Robin stopped being friends.
Marshall: Of course. Robin hates kids. The last thing she would want to do is hang out with some little brat.
Ted: Thus, if I may... [clears throat] When Glitter's womb a fruit did bear, Robin said, "To hell with this, I'm outta hare." [all confused] Glitter got pregnant, so Robin dumped her.
All: Oh.